1. Technical Field
The disclosure relates in general to a light scribe disc drive, and more particularly to a compensation method which compensates the voltage for moving the optical pick-up head of the light scribe disc drive to write a pattern in the radial direction on the label side of an optical disc.
2. Description of the Related Art
In general, an optical disc has two sides, namely, the data side and the label side. The data side is for storing the data written with an optical pick-up head, and the label side is for marking the contents of the data stored in the optical disc through the use of a sticker or a pen. Currently, a specific optical disc is provided. With the specific dye being coated on the label side and the use of specific light scribe disc drive and writing program, desired patterns and texts can be easily written on the label side, making the optical disc more versatile and personalized.
As indicated in FIG. 1, a light scribe disc drive writing an optical disc according to related arts is shown. During the writing process, the light scribe disc drive 10 rotates a lead screw 12 with a step motor 11 for moving an optical pick-up head (OPU) 13 to a fixed point in the manner of coarse adjustment first. Then, a voltage generates a corresponding electromagnetic force which drives the lens 14 to displace within the track field covered by the fixed point in the manner of fine adjustment, and the writing of the optical disc 15 is done through focusing and tracking. After the writing on the track field of a fixed point is completed, the OPU 13 is displaced to the track field of the next fixed point in the manner of coarse adjustment, the lens 14 is displaced in the manner of fine adjustment, and the writing on the track field is repeated to complete the writing of the optical disc.
However, in actual practice, the fine adjustment in the displacement of the lens 14 may not be done precisely through the use of a driving voltage due to the factors such as the temperature, voltage and mechanical tolerance of the light scribe disc drive. As indicated in FIG. 1, when the OPU 13 writes on an optical disc 15 from inner rings to outer rings, the displacement of the lens 14 driven by the same magnitude of voltage diminishes from distance W1 in inner rings to distance W2 in outer rings, and displacement offset occurs accordingly. However, such displacement offset can be compensated by marking the address of the data track 17 during the writing of the data side 16.
Since the label side 18 is lack of data track, the problem of displacement offset cannot be resolved by way of marking address when writing a pattern on the label side 18. Thus, when drawing a pattern on the label side 18, the lines are inconsistent, and the pattern cannot be written uniformly. Thus, the issue of compensating the voltage in the radial direction on the label side of an optical disc in related art still has many problems to be resolved.